Page 4 - 2.Lesson_notes-Reproduction_in_human_beings

 Vagina is a muscular tube whose walls contain elastic tissue. It receives the
sperms during copulation. Vagina is also called the birth canal.
 In human females, the urinary opening and vaginal openings are separate.

Fertilization-

 It is the process of fusion of the male gamete, or sperm, with the female
gamete, or ovum to form a diploid zygote.

Structure of sperm Structure of ovum

The close attachment of the growing foetus to the thickened wall of the
uterus is called implantation which takes place seven days after fertilization.

 The placenta is an organ that establishes an intimate connection between the
foetal membrane and the uterine wall.

 Here the exchange of material between the mother’s blood and the blood of
foetus takes place.

 It provides oxygen, nutrients, water, minerals, vitamins, etc. to the growing
foetus from the maternal blood and removes wastes, carbon dioxide, urea,
etc. from the foetal blood. Thus, the placenta serves as the nutritive,
respiratory and excretory organ of the foetus.

4